Stream: general

Topic: ✔ Import from other .wit file

Xe Iaso (May 19 2025 at 15:04):

Oh, my expectation was that .wit files were kinda like protobuf files in that you can just have them mutually import eachother and have a "bank" of shared APIs, each with different packages.

EG:

wit
└── techaro
    ├── logger.wit // package techaro:logger
    └── wasm-checker.wit // package techaro:wasm-checker

Is this not really designed for the monorepo case where you have a big generic library full of stuff and then your components reach into and pull from part of that?

Your example for simple WIT reuse is something I wish was in the docs because I didn't know where to put the files in order to make things Just Work:tm:. Is there a way to do this that doesn't involve having to make symlink farms for deps folders?

Ramon Klass (May 19 2025 at 15:10):

if you have a monorepo with lots of separate packages, a wit/ directory that has no wit files but only a deps/ directory with all named packages is fine too, then everything in your repo can refer to worlds by their package names

Xe Iaso (May 19 2025 at 15:13):

you can refer to the world by the full legal package name?

Xe Iaso (May 19 2025 at 15:14):

reading https://docs.rs/wit-bindgen/latest/wit_bindgen/macro.generate.html#options-to-generate doesn't give me the impression you can do that

Xe Iaso (May 19 2025 at 15:15):

putting in techaro:wasm-checker/checker works

Ramon Klass (May 19 2025 at 15:16):

yes you can refer to worlds with their full path for your use case :)

Xe Iaso (May 19 2025 at 15:17):

moving everything to a deps folder makes wit-bindgen break:

wit
└── deps
    ├── techaro:logger
    │   └── logger.wit
    └── techaro:wasm-checker
        └── wasm-checker.wit

$ cargo build --target wasm32-unknown-unknown --release
   Compiling is-modern-browser v0.1.0 (/Users/cadey/Code/Techaro/hivemind/wasm/is-modern-browser)
error: failed to resolve directory while parsing WIT for path [/Users/cadey/Code/Techaro/hivemind/wit]

       Caused by:
         failed to parse package: /Users/cadey/Code/Techaro/hivemind/wit

       Caused by:
         no `package` header was found in any WIT file for this package
 --> wasm/is-modern-browser/src/lib.rs:5:1
  |
5 | / wit_bindgen::generate!({
6 | |     world: "techaro:wasm-checker/checker",
7 | |     path: "../../wit",
8 | |     generate_all,
9 | | });
  | |__^

Ramon Klass (May 19 2025 at 15:18):

oh I thought that was fixed, your wit/ needs to define a package name which can just be package unused:unused; which is not intended, a wit directory purely with deps in it is supposed to be fine

Xe Iaso (May 19 2025 at 15:19):

ah, i see, that makes it work

Notification Bot (May 19 2025 at 15:26):

Xe Iaso has marked this topic as resolved.

Xe Iaso (May 19 2025 at 15:42):

https://github.com/bytecodealliance/wit-bindgen/pull/1299 filed a docs PR

Last updated: Dec 06 2025 at 05:03 UTC